In the sport of golf a player advances a golf ball along a predetermined course by striking the ball with a golf club(s). Portions or legs of most golf courses along which players must advance their golf balls are often hundreds of yards long and are such that golfers must strike their golf balls with great force and velocity to drive the balls as far as possible in order to complete such legs of the courses with as few strokes as possible. The art of striking golf balls great distances is referred to as driving and is distinguished from the arts of striking golf balls short distances, which are generally called chipping or putting.
The art of driving golf balls requires the exercise of great and special skill. If balls are to be driven effectively great distances, they must be struck with clubs that are swung with great velocity and force. If the balls are to reach the areas of the courses which the golfers have targeted, the clubs must strike the balls at proper predetermined angles. When the angles at which the balls are struck deviate laterally from proper angle to cause the balls to be driven to the left of the golfers (right-handed) and of their intended targets, they are said to have been "hooked"; and, when so struck to cause the balls to be driven to the right of their golfers and their intended targets, they are said to have been "sliced." Since golf balls travel great distances when driven, when the angle at which they are hit is slightly misdirected or off angle, such slight off angle often results in the driven balls coming to rest at points that are far removed from their targets and, not infrequently, are driven out of the prescribed playing areas or bounds of the courses.
As a result of the foregoing, it is generally necessary that those who play golf spend many hours practicing the driving of golf balls to first develop and thereafter maintain practical driving skills.
To the above end, most golfing facilities provide golf ball driving ranges where golfers can practice driving golf balls to develop and hone their driving skills. Unfortunately, most golfers find that they have too little free time to make arrangements to visit and effectively utilize such driving ranges. Most golfers find that utilizing such ranges is inconvenient and impractical for reasons too numerous to be enumerated.
As a result of the above, there has been a long recognized need for a practical and serviceable devise that will enable golfers to practice driving golf balls at their homes, offices and other convenient sites where time and circumstances will best allow them to practice.
To the above end, the prior art has sought to provide golf ball driving practice devices which are such that they can be effectively set atop the ground or an appropriate deck wherever there is sufficient room for golfers, standing adjacent the devices and with golf clubs in hand, can fully and forcefully swing the clubs, to strike the golf balls that are a part of the devices, as though they were striking the balls while playing golf.
The most basic and practical kind of golf practicing devices provided by the prior art consist of an elongate vertical support or frame set upon the ground; and elongate horizontal arm projecting from the frame and having an outer free end spaced above a point on the ground where a golf ball might be advantageously set and struck with a club; a bearing at the outer end of and concentric with the longitudinal axis of the arm; an elongate connector part with an inner end connected with the bearing and normally depending from the bearing and the arm to near said point on the ground; and, a ball secured to the other free end of the connector part to normally occur in running clearance above said point on the ground. Upon striking the ball with a golf club, to drive it on the radial planes of the bearing, the ball is caused to rotate about the free end of the arm. The velocity at which the ball is driven determines the number of times the ball will turn about the arm. The number of times the ball turns about the arm is substantially proportional to the distance the ball would have traveled if it was free (unconnected) when struck or driven. Accordingly, the prior art has provided such devices with counting means that count the numbers of times the balls turn about the arms when driven and that translate the numbers of turns counted into the numbers of feet or yards the balls would have traveled if free when struck.
Prior art devices of the class briefly described above and here concerned with have proven to be seriously defective or wanting when the golf clubs miss the ball and strike the connector parts. If the connector parts are rigid metal parts, they are bent out of shape when so hit and must be carefully bent back into shape. They can only be bent out of and back into shape a rather limited number of times before they work harden and break. If they are made heavy and strong enough so that they will not readily bend out of shape when hit with golf clubs, they do irreparable damage to the clubs when they are hit thereby.
If the connector parts are flexible lines, such as wire cables, when they are struck by golf clubs they tend to wrap around the clubs or otherwise establish a purchase thereon with disastrous results. For example, the golfers can be seriously injured or their clubs and/or the devices can be irreparably damaged.
The noted prior art devices have also been found to be seriously deficient or wanting when golfers hook or slice the balls when striking them with their clubs. When the balls are hooked or sliced, they are caused to rotate eccentrically and wobble or gyrate violently about the axes of their related bearings and arms. The wobbling action tends to move the devices out of position. The eccentrically gyrating balls are subject to striking parts of the devices, the golf clubs and the golfers. More important and serious is the fact that when the balls are hooked or sliced and are caused to gyrate eccentrically as noted above, the misdirected dynamic forces are concentrated on the connecting parts where they join their bearings; causing those parts to bend back and forth repeatedly. The connecting parts soon work harden and break. They usually break at a time when the balls are initially impacted by clubs, with the result that the balls and their connecting parts are driven away, free from the devices, and are subject to doing great injury and/or damage.
There are some in the prior art who have sought to overcome the last-noted shortcoming in "tethered ball" type devices by providing self-aligning or shiftable bearing means that are intended to reduce the stress on the connecting parts where they join the bearings and that tend to let the balls gyrate more freely. While those efforts have reduced the rate at which the connector parts work harden and break to a notable extent, they ascerbate the hazards created by the eccentrically gyrating balls.
In other attempts to reduce the problems noted above, there are those in the prior art who have adopted and used light-weight simulated golf balls to reduce those potentially dangerous and/or damaging dynamic forces that are encountered when the balls are caused to gyrate eccentrically. The problem with using light-weight balls resides in the fact that they simply and clearly do not sound, feel or react like real golf balls when hit by a golf club.
U.S. Pat. No. 2,470,807, issued May 24, 1949 to C. F. Davis, Jr., discloses a golf practicing device of the general character here concerned with that includes a rigid shaft-like connecting part rotatably supported on a horizontal arm. The lower end portion of the connecting part is enlarged and angularly off-set. A simulated golf ball is connected to the lower end of the connecting part by a shock-absorbing means. A distance-indicating dial is driven by the shaft through or by means of an intermediate reduction gear train. Special effort is made to mount the ball remote from the connecting part so that it is less likely to be hit by a golf club. Striking the shaft with a golf club is likely to cause irreparable damage to both the shaft and the club. No provision is made to deal with those adverse dynamic forces that are encountered when the ball is sliced or hooked when struck by a club.
U.S. Pat. No. 2,929,632, issued May 22, 1960 to C. D. Moffatt, teaches the basic kind of practice device here concerned with, wherein a light-weight ball is carried at the end of an elongate flexible wire cable that extends to and is connected with an annular bearing ring on a horizontal arm. The bearing is in space relationship between two widely spaced stops on the arm and between which the ring can freely slide back and forth when the ball is sliced or hooked, when hit by a club. Thus, premature work hardening and breaking of the cable, where it connects with the bearing ring, is reduced.
U.S. Pat. No. 4,113,257, issued Sept. 12, 1978 to C. D. Moffatt, teaches an improved simulated golf ball for use in the device which is the subject matter of U.S. Pat. No. 2,929,632.
U.S. Pat. No. 4,496,156 issued Jan. 29, 1985 teaches a device similar to the Moffatt device but in which the means connecting the ball to the bearing on the arm is an articulated assembly including both rigid and flexible sections. The rigid section is carried by an axially shiftable bearing ring or sleeve and carries a pusher means that engages and actuates a button counter on the arm. The button counter displays the number of times the ball turns about the arm each time the ball is struck. The number of turns counted by the counter indicates the distance the ball would have traveled if it were free when struck.
U.S. Pat. No. 4,861,035 issued Aug. 31, 1989 to J. V. Page, teaches yet another form of the basic kind of device here concerned with. In this device a flexible tether for the ball is intentionally caused to wrap around an arm to cause the ball to strike and close a switching device on the arm when the ball is struck squarely. When the switching device is closed, a bell or other signalling device is sounded.
U.S. Pat. No. 4,932,660 issued June 12, 1990 to A. Wang, teaches an improved bearing means for the basic form of device that is taught by the above-noted patents to Moffatt. Wang's improved bearing includes a semi-universal ball joint to which the cable tether is connected. The universal ball joint, in addition to preventing work hardening of the cable tether, serves to prolong eccentric gyrating of the ball, when it is sliced or hooked when struck. Prolonged eccentric gyration of the ball affords the golfer time to observe the extent to which the ball is gyrating and thereby better appreciate the extent to which the ball was hooked or sliced.
U.S. Pat. No. 3,406,571 issued Oct. 22, 1968 to D. Hackey; and, U.S. Pat. No. 4,848,769 issued July 18, 1989 to J. A. Bell, et al., are of particular interest in that they show golf practice devices which are quite different from the basic kind of device which is the subject matter of the several above-noted patents, but in which the same or similar ends are sought to be obtained.